Ultrasonography, Doppler, TranscranialCerebrovascular CirculationDominance, CerebralUltrasonography, DopplerLanguageFunctional LateralityBlood Flow VelocityUltrasonography, Doppler, ColorTranscranial Magnetic StimulationEchoencephalographyCerebral ArteriesUltrasonographyMiddle Cerebral ArteryIntracranial Embolism and ThrombosisIntracranial PressureValsalva ManeuverUltrasonography, Doppler, PulsedBrain Hemorrhage, TraumaticCerebrovascular DisordersAnemia, Sickle CellHeart Septal Defects, AtrialArterial Occlusive DiseasesIntracranial EmbolismEvoked Potentials, MotorDoppler EffectIschemic Attack, TransientCerebral AngiographyProspective StudiesPulsatile FlowCarbon DioxideStrokeBrain IschemiaUltrasonography, PrenatalBrainMotor CortexBlood PressureSensitivity and SpecificityRegional Blood FlowEchocardiography, Doppler, PulsedCarotid StenosisEchocardiography, Doppler, ColorUltrasonography, Doppler, DuplexCarotid Artery, InternalBasilar ArteryMonitoring, IntraoperativeCircle of WillisEmbolism, AirUmbilical ArteriesReproducibility of ResultsPredictive Value of TestsVascular ResistanceOphthalmic ArteryContrast MediaCarotid Artery DiseasesUltrasonicsEndarterectomy, CarotidHemodynamicsVertebral ArteryTomography, X-Ray ComputedCerebral Arterial DiseasesMagnetic Resonance ImagingVasospasm, IntracranialEmbolism, ParadoxicalMonitoring, PhysiologicPlacental CirculationPregnancySubclavian Steal SyndromeAcetazolamideCollateral CirculationHypocapniaTime FactorsReference ValuesForamen Ovale, PatentAngiography, Digital SubtractionIntracranial Arterial DiseasesPortal VeinPyramidal TractsSubarachnoid HemorrhageScrotumLaser-Doppler FlowmetryCarotid ArteriesTreatment OutcomeConstriction, PathologicElectromyographyObserver VariationArteriesFetal DiseasesMagnetic Resonance AngiographyTesticular DiseasesPhosphenesSkullElectric StimulationIntracranial HypertensionHepatic VeinsHomeostasisFollow-Up StudiesUterusAcute DiseasePortographyHyperventilation